The classic editor does not save change

I have a big problem that I have been trying to solve for almost a month, but to no avail

I used the classic editor naturally but everything changed when I started working with cache plugins

Become the classic editor does not save any change
Example If you open to the post and change the link to the topic or anything and click on Save

I get a message I have updated the post but in fact everything is back as it was before the update and nothing is updated

After that I wiped the cache and wiped the add but nothing came back as it was

Quite the opposite when using the new Gutenberg editor

Changes are saved naturally without problems

But I don’t want Gutenberg editor I can’t work on it

Just want to work on the classic editor

I want to help